{"id":"AZL-74306","summary":"CVE-2025-68796 affecting package kernel for versions less than 6.6.121.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to avoid updating zero-sized extent in extent cache\n\nAs syzbot reported:\n\nF2FS-fs (loop0): __update_extent_tree_range: extent len is zero, type: 0, extent [0, 0, 0], age [0, 0]\n------------[ cut here ]------------\nkernel BUG at fs/f2fs/extent_cache.c:678!\nOops: invalid opcode: 0000 [#1] SMP KASAN NOPTI\nCPU: 0 UID: 0 PID: 5336 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full)\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014\nRIP: 0010:__update_extent_tree_range+0x13bc/0x1500 fs/f2fs/extent_cache.c:678\nCall Trace:\n \u003cTASK\u003e\n f2fs_update_read_extent_cache_range+0x192/0x3e0 fs/f2fs/extent_cache.c:1085\n f2fs_do_zero_range fs/f2fs/file.c:1657 [inline]\n f2fs_zero_range+0x10c1/0x1580 fs/f2fs/file.c:1737\n f2fs_fallocate+0x583/0x990 fs/f2fs/file.c:2030\n vfs_fallocate+0x669/0x7e0 fs/open.c:342\n ioctl_preallocate fs/ioctl.c:289 [inline]\n file_ioctl+0x611/0x780 fs/ioctl.c:-1\n do_vfs_ioctl+0xb33/0x1430 fs/ioctl.c:576\n __do_sys_ioctl fs/ioctl.c:595 [inline]\n __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7f07bc58eec9\n\nIn error path of f2fs_zero_range(), it may add a zero-sized extent\ninto extent cache, it should be avoided.","modified":"2026-04-01T05:22:42.565437Z","published":"2026-01-13T16:16:01Z","upstream":["CVE-2025-68796"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-68796"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.121.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-74306.json"}}],"schema_version":"1.7.5"}